Use of antipsychotic medications was associated with an increased risk of head injuries in a study of individuals with Alzheimer's disease published in the Journal of the American Geriatrics Society.

Antipsychotic use is associated with risk of falls among older persons, but previous studies have not investigated the association of antipsychotic use and risk of head injuries among community dwellers with Alzheimer's disease.

The nationwide study of individuals in Finland who were diagnosed with Alzheimer's disease from 2005 to 2011 included 21,795 patients who started taking antipsychotic medications and 21,795 patients who did not. Use of antipsychotic medications was linked with a 29% higher risk of head injuries (the "event rate" was 1.65 versus 1.26 per 100 person-years in users versus non-users).

This means there would be an average of 1.65 versus 1.26 injuries among 100 people over one year. This translates to 165 versus 126 injuries per 10,000 people. Also, use of antipsychotic medications was linked with a 22% higher risk of traumatic brain injuries (0.90 versus 0.72 per 100 person-years).

Antipsychotic use should be restricted to most severe neuropsychiatric symptoms

When comparing antipsychotic medications, quetiapine users had 60% higher risk of traumatic brain injuries compared with risperidone users.

These findings imply that in addition to previously reported adverse events and effects, antipsychotic use may increase the risk of head injuries. Therefore, their use should be restricted to most severe neuropsychiatric symptoms, as recommended by the AGS Beers Criteria. Additionally, the higher relative risk of traumatic brain injuries in quetiapine users compared to risperidone users should be confirmed in further studies.

Lead author Vesa Tapiainen, MD, of the University of Eastern Finland, said: "Persons with Alzheimer's disease have a higher risk of falling, head injuries, and traumatic brain injuries and worse prognosis after these events in comparison to those without Alzheimer's disease.Therefore, it is important to avoid further increasing risk with antipsychotics in this vulnerable population, if possible."